Universal joint for grinding-mills.



E. C. GRIFFIN, DECD. L. M. GRIFFIN; BXIIUUTR'IX.

UNIVERSAL JOINT FOR GRINDING MILLS.

APPLICATION FILED MAY 4, 1912.

i' 1,048,3. f Patented 136624,1912.

EDWIN C. GRIFFIN, lm' GRIFFIN, EXEC/ li.'

PULVERIZER Gi., f

,.ASED, LATE OF NEWTON, MASSACHUSETTS, BY LOVINA M. GF ASHMNT,MASSACHUSETTS, ASSIGNOR TQ BRADLEY STCE, ifiESr'CHUSETIS, A CORPORATIONOF MAINE.

Specification of Letters Patent.

Patented Dec. 24, 1912.

delineation :"ied a, 1912. Serial No. 695,179.

To all whom z'z may co Be it known that ceased, late of NeyY y sex,State of Massa i did invent an Improvement in Un `sal Joints forGrinding-Mills, of which the following de scription, in connection withthel accompanying drawing, is a specification, like characters on thedrawing represent-ing like parts.

This invention relates more particularly tomills for pulverizing orgrinding rock, ore,islag or other refractory lmaterial. by the act1on ofa suspended revoluble roll havmg a gyratory action with relation to thesuspension. means therefor and which coperates with an annular die, amill of this type being shown in United States Patent No.

(l Gruissan, de ny of Middlel1,020,092, dated March l2, 1912. In suchmills the suspending means usually includes an overhead and suitablysupported driving shaft having an attached pulley connected by beltingWith a proper source of power, the grinding roll shaft beingconnectedwith such overhead shaft by a substantially universal coupling,in such manner that the roll .shaft is suspended and rotated positivelyWithout interference with the ratory mo- ,tion thereof when the mill is'in operation..

The coupling comprises essentially a rotating outer member and aninclosed coperating rocking member which is rotated bodily andpositively in unisonv with the outer member, the latter being iixedlyattached to the driven shaft. This inner member is made as a cross-headhaving radial arms or trunnions extended laterally' therefrom andcarrying segments which have their bearings on concave seats inthe outermember, as for instance in Patents No. 721,035 dated February 17, 1903,and No. 922,579 dated May 25, 1909. As shown therein the head has acentral tapered hole to receive the correspondingly ta;y the roll shaft,Whit.. is eid in the crosshead by a nut screwed onto the threadedextremity of the shaft projecting above the top of the cross-head. hasbeen found in practice that this construction is objectionable, forthejar and shock to which the parts arc subjccted'by the operation ofthe mill tend to loosen the retaining nut, so that the roll shaft is notheld as rigidly and red upper end of' be ,effected easily and rapidlywith a minimum expenditure of time and labor.

The Various novel features of the invention will be fully described inthe subjoined specification and particularly pointed out in thefollowing claims.

Figure l is a view in elevation and section of a sufficient portion of agrinding mill of the type referred to, with a practical form of thepresent invention embodied therein; Fig. 2 is an enlarged top plan Viewof the cross-head from which the roll shaft is suspended, showing theseats for the sliaft-i'etaining member; Fig. 3 is a right hand sideelevation of the cross-head, the tapered end of the roll shaft and theretaining member therefor being shown by dotted lines; F ig. 4 is avertical section of the crosshead taken through the Center thereof onthe line 4-4, Fig. 3.

Referring to Fig. l, the frames 15 carrying the annular member 17 whichforms a concave seat for the bearing 19, the cross piece 2() supportedby the frame, 16, and sustaining t e seat 21 for the bearlng 22 of thedepending shaft 27, having its ower end securcdin the hub 28 of thedriving pulley 29; the tubular port-ion 30 bolted to and depending fromthe pulley hub and terminat` ing in a flared tubular extension 3l ontowhich the bearing 19 is clamped; the annular internal shoulder 32, andthe concaved bearing ring 33, may be and are all substantially as inPatent No. 1,020,092. The hub 28 and attached depending portion 30constitute an inclosed outer or socket member of the coupling whichconnects the suspending shaft 27 and the suspended roll shaft, to

made as helical surfaces, the low portions of are diametrically disposedand upright eon-4 cave seats 50, 50 each seat being conveniently made intwo parts, as shown, and coperating with the convex end faces ofsegments 51 centrally apertured to fit easily upon oppositely extendedarms or trunnions 52 which project radially from a cross-head 53. Thecross-head has a tapered axial hole 54 for the reception of thecorrespondingly tapered upper -end 55 of the roll shaft 56, Fig. 1, itbeing understood that said shaft in practice carries. at itslower end. asuitable grinding roll, as in Patent No. 1,020,092.

The described structure provides a universal coupling between'the shafts27 and 56, as will be apparent, in a manner similar to the couplingsshown in Patents Nos. 721,035 and 922,579, the Weight of the roll shaft,roll and cross-head bein sustained by the suspension member 57 ,ma e asa spherical segment and seated in the concaved bearing 33. As suchsegment is subjected to hard wear it is made of manganese steel or othersuitable wearresisting metal, and separate from the crosshead, so thatit can be readily renewed when necessary, the segment being aperturedcentrally for the shaft, the bottom of the crosshead seating upon theflat upper face of the segment. Herein the retaining nut for the rollshaft, and the threading of the latter for the nut, are obviatedaltogether, and instead of such retaining means a steel pin 58 is driventhrough a 'transverse hole in the tapered part of the roll shaft, theprojectin ends of the pinv resting upon diametrica v opposite cam seats59 formed on the top of the cross-head. Said cam seats are oppo- Sitelyinclined, as shown, and preferably are said seats being adjacentabutments 60,' the abutments being parallel to each other and offset atopposite sides of a diameter through the axial center ofthe crossfhead,as shown in Fig. 2.`

- When assembling the 'cross-head and roll shaft the tapered end 55 ofthe latter is inserted in the hol'ef5fi of the cross-head and theretaining pin 58' is driven into positionA through lthe shaft, the endsof the pin resting on tlie'cani seats at their low points, adjacent theabutlnents G0. The exact position of the pin' on the seats depends uponthe fit of the shaft in the hole 54, the farther inthe shaft extends thehigher upon the seats willy the ends of the pin rest initially. Rotationof the cross-head lis in the direction of the p arrow, Fig. 2,that is,from the high toward the low 'arts of the cam seats, in conse-- quence owhich the project-ing ends of the 'pin alweysfutend'i'totravel towardthe high `parts of 'theseatsf This coperation of the ""pin and 4the camseats acts `to pull the shaft upward. intro its tapered hole 54 intheloross head, as w1 be manifest, so thatl the reater the resistancf`to rotation offered yg the shaft the more securely and firmly will thedescribed connection draw together the shaft and cross-head. i

As the parts are all inclosed and have no relative movement, once theshaft and cross-head have been drawn together by the described camaction, it will be obvious that there 'is no wear, and the connectionwill last indefinitely.

It is impossible loose in the cross-head when the mill is in for theshaft to become operation, manifestly, owing to the selttighteningaction of the connection between such parts, yet when it is necessary toseparate the parts it can be easily effected b reversing the rotation ofthe 4crosshea ,as thereby the.ends of the retaining pin are caused totravel down the helical seats toward the abutments. i

The trunnions are made hollow, as shown, for the reception of lubricant,and oil holes 61 are drilled through the cross-head and through thesuspending segment 57, Fig. 4.

Oil ducts 62 lead through the pulley hub 2S to the interior thereof froma lubricating cup or chamber 63 bolted to the hub and surrounding theshaft 27, whereby the lubricantcan be introduced to the interior of theinclosingor socket member of the shaft-cou` pling.

The particular construction of the shaftcouplingmay be varied orrearranged as may be convehient, and various other parts of theapparatus may be changed orniodified without interferinr or departingfrom the spirit and scope o the present invention as set forth in the.claims hereunto annexed.

Having fully described the invention, what is claimed and desired to beysecured by Letters Patent is:

1. In a grinding mill of lthe class described, a driving shaft, asuspended roll shaft having a tapered upper end, a universal Vcouplingincluding an inclosing member attached to the driving shaft and aninclosed rocking lnember having a tapered holel for the upper end ofvthe roll shaft, oppositely inclined cam seats on the top of the inclosedmember adjacent the shaft hole, und a retaining pin extended through theprojecting end of the shaft and having its opposite ends resting uponthe seats, whereby rotation of the coupling in the direction of thelower portions of the cam seats causes the latter to coperate with theretaining pin and draw the roll'shaft and cross-head together.

2. The combination with a driving shaft, 'a suspended shaft to bedriven, and a universal coupling between them and from which the drivenshaft is suspended, the coupling including a member having a taperedhole for the correspondingly tapered upper end of the suspended shaft,of arr automatically tightening connection between said shaft andcoupling membery comprising oppositely inclined cam seats on the top ofthe coupling member and radial projections on the tapered end of theshaft resting upon and'upheld by the cam seats.

3. The combination with a driving shaft, a suspended shaft to be driven,and a universa-1 coupling between them and from which the driven shaftis suspended, the coupling including a member having a tapered hole forthe correspondingly tapered upper end of the suspended shaft, of anautomatically tightening connection between said shaft and couplingmember, compris# ing seats on the top of the coupling memberdiametrically oppo'site each other and having oppositely inclinedhelical surfaces, and a pin extended through the projecting end of theshaft and resting upon the helical surfaces at opposite sides of theshaft.

4. In a grinding mill, an overhead driving shaft, a suspended gyratoryroll shaft,

'Aa universal coupling between the shafts and from which the 4roll shaftis driven, the coupling including an inclosed rocking cross-headhavingian axial, tapered hole for the correspondingly tapered upper endof thel roll shaft, oppositely inclined helical seats on the top of thecross-head at opposite sides of the shaft hole, and a coperating pinpassed through the shaft above the crosshead, the projecting ends of thepin resting upon and being 'supported by the seats, rotation of thecoupling toward the low portions of the seats causin the pin to travelup said seats and thereby draw the shaft tightly into the cross-head.

5. In a grinding mill, an overhead driving shaft, a Asuspended gyratoryroll shaft, a universal couplingpbetween the shafts and from which theroll shaft is driven, the coupling comprising an outer member providedwith an annular, coaxial bearing, and a cross-head mounted to rock inthe outer member and having a tapered axial hole for the correspondinglytapered end of the roll shaft, a suspendingHmember surrounding the shaftand interposed between the crosshead and said annular bearing, and anauto'- matically tightening connection between the roll shaft and thecross-head, comprising oppositely inclined helical seats on the top ofthe latter and a transverse p'in carried by the shaftand resting uponthe seats', operative rotation of the coupling causing the pin to travelup the seats and thereby draw the roll shaft tightly into thecross-head.

In testimony whereof, I have signed my name to this specification, inthe presence of two subscribing witnesses.

LOVINA M. GRIFFIN, E'ecuzfrz'x of estateEdfwz'n O'. Grfin, (Zeceased. f

lVitnesses:

J. E. GRIFFIN, FRED M. MoN'rGoMEnY.

